This invention relates to a ribbed flange seal for a gas turbine engine and, more particularly, the invention is concerned with providing strengthening ribs of arcuate configuration extending outwardly from the walls of adjacent flanges so that fewer bolts are needed to join the sections while effectively maintaining a positive seal between the sections.
Heretofore, it has been common practice to attach the several sections of large turbojet and turboshaft engines to each other by bolting the flanged sections to one another. A large number of closely spaced bolts are required in order to maintain a tight dependable seal between the sections. Each of the bolts must be provided with a nut and each must be lockwired to prevent loosening. Since the flange on each section is generally quite thin to save weight, the bolts are spaced in a typical engine at 4 times the bolt diameter requiring as many as 210 bolts per flange to provide the necessary seal. It can be seen that the assembly procedure can be very time consuming as well as costly in terms of the bolts, nuts and lockwiring involved. Also, the time required to drill and counterbore the many holes for the nuts and bolts can add greatly to the cost of assembling the engine.
It would be desirable to provide a sealing arrangement between the sections of the engine whereby assembly could be accomplished with a minimum number of bolts, nuts and lockwires and where the flange still serve to maintain a tight seal between sections. Also, the strength and rigidity of the flange must be sufficient while the weight of the completely assembled engine must be held within tolerable limits. The hereinafter described modified flange sealing arrangement does provide a suitable seal without adding weight and, at the same time, reducing the cost of hardware required for assembly.